B&R X20cSC2212 Manual page 19

8.2.2 Connecting single-channel sensors with contacts
By default, every input channel is assigned a dedicated pulse output. This pulse output issues a specific signal
that helps detect wiring problems, such as a short circuit to 24 VDC, GND or other signal channels. The status
of the connected switches is indicated by channel-specific LEDs. The LEDs "OO" and "OC" have no significance
with this type of connection.
With this type of connection in combination with the configuration "Pulse Mode = Internal", the modules can detect
the following errors:
Ground fault on the pulse output
Pulse output shorted to 24 VDC
Cross fault between the pulse output and the other pulse signal
Ground fault on signal input
Signal input shorted to 24 VDC
Cross fault between the signal input and the other pulse signal
Cross fault between the pulse output and the signal input
Open circuit
8.2.3 Connecting two-channel sensors with contacts
By default, every input channel is assigned a dedicated pulse output. This pulse output issues a specific signal that
helps detect wiring problems, such as a short circuit to 24 VDC, GND or other signal channels.
The status of the connected switches is signaled via channel-specific LEDs, and the status of the dual-channel
evaluation is signaled via the "OO" (for combinations with N.C./N.C. contacts) or "OC" LED (for combinations with
N.C./N.O. contacts). On module types that do not have these LEDs, errors detected in the dual-channel evaluation
are indicated by the respective channel LED blinking red.
With this type of connection in combination with the configuration "Pulse Mode = Internal" and combined with dual-
channel evaluation in the module or in SafeDESIGNER, the modules can detect the following errors:
Ground fault on the pulse output
Pulse output shorted to 24 VDC
Cross fault between the pulse output and the other pulse signal
Ground fault on signal input
Signal input shorted to 24 VDC
Cross fault between the signal input and the other pulse signal
Cross fault between the pulse output and the signal input
Open circuit
1) Dual-channel evaluation of the module.
Data sheet V1.141 X20(c)SC2212 Translation of the original documentation
Error
Table 10: SI error detection when "Pulse mode = Internal"
Error
Table 11: SI error detection with "Pulse Mode = Internal" combined
with dual-channel evaluation in the module or in SafeDESIGNER
X20(c)SC2212
Error on contact
Open
Detected
Detected
Detected
Not detected
Detected
Detected
Not detected Not detected
Not detected Not detected
Error on contact
Open
Detected
Detected
Detected
Not detected
Detected
Detected
Detected Not detected
1)
Not detected
Detected
Closed
Detected
Detected
Detected
Detected
Detected
Detected
Closed
Detected
Detected
Detected
Detected
Detected
Detected
1)
19